NEW DELHI, April 16 -- India's senior-most military commander on Thursday flagged concerns about disruptors stepping in to fill the vacuum that will be created in Afghanistan with the withdrawal of American and North Atlantic Treaty Organisation (NATO) troops, possibly resulting in violence continuing in that country. US President Joe Biden announced on Wednesday that the remaining US troops will leave Afghanistan by September 11, the 20th anniversary of the 9/11 attacks that took them there in the hunt for Al Qaeda....